1. Field of the Invention
The invention relates to a method of controlling a clutch with motorized actuation, and is concerned more particularly with an improvement making it possible to achieve a better control of the actuating stroke of the clutch and, additionally, a control of the state of the clutch over its entire operating life.
2. Description of the Prior Art
A clutch with motorized actuation and suitable for a motor vehicle is known, in which the conventional clutch pedal and the linkage connecting this pedal to the clutch fork are omitted. All these elements are replaced by a mechanism comprising an electric motor and an actuator associated with a spring compensator designed to moderate or regulate the torque which the motor must exert over the entire length of an engaging or disengaging stroke. This spring compensator thus makes it possible to use an electric motor of relatively low power. Such a clutch system is described, for example, in French Patent Application No. 82.04,603 filed by the Applicant. Moreover, electrical control means for the motor have already been described in French Patent Application No. 83.01,748, making it possible to use a conventional direct-current electric motor, the position of which is controlled by a series of electrical pulses. This avoids the need to use a bulky and costly stepping motor, whilst at the same time saving response time. In such a context, therefore, it is important, at any moment, to known and control the position of the actuator (that is to say, the position of the clutch bearing along the driven shaft or what amounts to the same thing, the angle of rotation of the fork coupled to this bearing, or even the position of the reducer mounted at the output shaft of the electric motor) over the entire length of an engaging or disengaging stroke and also for the entire operating life of the clutch, at the same time taking into account the changes in the mechanical characteristics of the system caused by the wear and/or fatigue of certain components. Such knowledge of the position of the bearing at all times makes it possible to control its movement more effectively; it is then possible to ensure that this can be reproduced closely, and to increase the driving comfort of the vehicle. This invention meets all these requirements.